JPH0159469B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a motion conversion device.

One aspect of the present invention is a cam mounted to rotate around an eccentric shaft that is eccentric with respect to a central axis, the eccentric shaft being rotatable around the central axis, and the cam having N protrusions. cams having a protrusion whose outermost position is located at an equal distance from the eccentric axis, and which are arranged at equal intervals around the eccentric axis, where N is an odd integer other than 1; A drive mechanism that provides relative rotation between the central shaft and the cam when the eccentric shaft rotates around the shaft, that is, when the cam rotates around the eccentric shaft.
2/ of the angular velocity of the eccentric shaft rotating around the central axis
It is composed of a drive mechanism that regulates the relative rotation between the central axis and the cam so that the cam rotates around the eccentric axis at an angular velocity of (N+1) times, and around an axis that substantially coincides with the central axis. a pair of rotatable cam followers, wherein the cam and the cam follower are arranged such that the cam follower is in contact with the cam on both sides of the central axis and is equidistant from the central axis, and the eccentric shaft moves around the central axis at a substantially constant speed. When rotated,
It consists of a cam curve that is formed so that the cam follower carrier that supports the cam follower undergoes one cycle of acceleration from a resting state and deceleration to a resting state 2N times each time it rotates. This is a motion conversion device characterized by being composed of a cam and a cam follower.

Throughout the specification, the term "rest" means a substantially or apparently zero velocity state, and in this so-called rest state, there is a possibility of having a relatively small but limited velocity. be.

The motion conversion device according to the present invention provides mutual conversion between constant angular velocity and periodic angular velocity.

The motion conversion device according to the invention can be applied to a type in which the first piston assembly and the second piston assembly operate within one working chamber. When the first piston assembly and the second piston assembly apply operating cycle angular velocities (different periodic angular velocities) to the two pairs of cam followers forming part of the motion conversion device,
Suitable for receiving "cat-mouse" differential motion. In addition, the "cat-mouse type" has members that rotate in pairs in the same rotational direction, that is, one member of each pair follows the other member, and these members periodically rotate. This refers to a type of rotation mechanism (hereinafter referred to as a "cat-mouse type") that rotates at varying angular velocities, and in which the volume of the space between the two members increases and decreases periodically as the rotation moves.

Such rotation mechanisms can be used in fluid pumps, fluid motors, internal combustion engines, and the like. Furthermore, such a rotation mechanism may have multiple actuation mechanisms, e.g.
The engine and the pump driven by the engine can be integrally configured.

Furthermore, the motion converting device of the present invention can be applied to other fields as a mechanism for indexing operations and for picking up articles from a storage location and returning them to the original storage location.

The present invention will now be described in detail with reference to various embodiments with reference to the accompanying drawings.

1 to 4, the motion conversion device of the first embodiment has a crankshaft 11,
This center of rotation forms the central axis 12. A cam 15 having a plurality of protrusions is rotatably mounted on the eccentric portion 13 of the crankshaft, and this cam 15 rotates around an eccentric shaft 16 that is eccentric with respect to the central axis 12. .

The cam 15 has N protrusions 17,
Here, N is an odd integer other than 1. As can be seen from the figure, the cam in this embodiment has three protrusions. The outermost position of each protrusion 17 is located at an equal distance from the eccentric shaft 16, and
They are arranged at equal intervals around the eccentric shaft 16, respectively.

The cam 15 is configured to rotate around the eccentric shaft 16 in the same direction as the crankshaft 11, and at an angular velocity that is 2/(N+1) times the angular velocity of the crankshaft 11. Therefore, in the case of this embodiment, the cam 15 rotates around the eccentric shaft 16 at an angular velocity that is half the angular velocity of the crankshaft 11.

As a mechanism for maintaining the angular velocity relationship between the cam 15 and the crankshaft 11, the cam 15
an internal gear 19 coaxial with the cam 15 and fixed to the cam 15;
is configured to mesh with an external gear 21 that is coaxial with the crankshaft 11 and fixed against rotation with respect to the fixed reference frame. Internal gear 1
The ratio of the number of teeth between 9 and external gear 21 is (N+1)/
2:(N+1)/2-1, so that the relationship in angular velocity between the cam 15 and the crankshaft 11 is maintained.

Note that as a mechanism for maintaining the relationship between the angular velocities between the cam 15 and the crankshaft 11, an appropriate drive means other than the one using the above external gear and internal gear, such as a belt drive, in short, the cam 15 crankshaft may be used. 2/(N+
1) Those skilled in the art will easily understand that any means that specifies rotation around the eccentric shaft 16 at twice the angular velocity is sufficient.

When the crankshaft 11 rotates, the cam 15
The motion is a combination of rotation around the eccentric axis 16 and revolution around the central axis 12. When the cam 15 makes this movement, the protrusion 1 of the cam 15
7 will move on an exotrochoidal trajectory.

The pair of cam followers 23 are rotatable around an axis that is substantially the same as the central axis 12 . In this embodiment, the cam follower 23 is a roller 25
The rotation axis is substantially parallel to the central axis 12. This cam follower 23
The rollers 25 are each mounted symmetrically on a cam follower carrier 27 rotatable around the central axis 12.

The distance between the contact surfaces of the two cam followers 23 in contact with the cams is determined by the distance between the outermost point of each protrusion 17 of the cam 15 (with respect to the eccentric shaft 16) and the diametrically opposite point of the cam surface. is substantially equal to the distance between In other words, when the eccentric shaft 16 is located closest to each cam follower 23, the distance from the central axis 12 to the contact point of the contact surface where each cam follower 23 contacts the cam is equal to the protrusion of the cam. It is substantially equal to the smallest radius of the outer trochoid locus formed by the tips of 17.

When the crankshaft 11 rotates at a substantially constant speed, the cam follower carrier 27 accelerates from a substantially zero speed state to a substantially zero speed state during one rotation of the cam follower carrier 27. The shape of the cam 15 is formed such that the cam follower carrier 27 receives one cycle consisting of 2N times of deceleration.

Thus, by imparting rotational movement to the crankshaft 11 with a substantially constant angular velocity, the cam follower carrier 27 is subjected to a periodic angular velocity. Similarly, by applying a periodic angular velocity of the same magnitude as the above-described constant angular velocity to the cam follower carrier 27, the crankshaft 11 comes to receive the above-described constant angular velocity.

Next, the operation of the motion conversion device shown in FIGS. 2 to 4 will be explained. Here, it is assumed that a constant angular velocity is given to the crankshaft 11 (the direction of rotation of the crankshaft 11 is indicated by arrow 2).
9).

In the position shown in Figure 2, the cam follower 2
3a is in contact with the tip of the protrusion 17a of the cam 15, while the cam follower 23b is in contact with the tip of the protrusion 17a of the cam 15.
It is in contact with a point on the cam surface on the diametrically opposite side of 7a. In this position, the eccentric shaft 16 is closest to the cam follower 23b, and the point of contact between the cam 15 and the respective cam follower 23 moves substantially tangentially to the rotational movement of the respective cam follower. Therefore, no driving moment is applied to the cam follower 23 by the cam 15. At this stage, the cam follower carrier 27 is at rest. In other words, the cam follower carrier 27 is substantially or apparently at zero speed.

As the crankshaft 11 continues to rotate, the eccentric shaft 16 moves away from the cam follower 23b, and the cam 15 rotates accordingly.
The drive moment that gradually increases is applied to the cam follower 2.
3b, the cam follower carrier 27 begins to undergo cycloidal acceleration.

In the position shown in FIG. 3, the cam follower carrier 27 is undergoing maximum acceleration. At the position shown in FIG. 4, the cam follower carrier 27 reaches its maximum speed, and at this position there is an inflection point where the acceleration changes from positive acceleration to negative acceleration (deceleration).

As the crankshaft 11 continues to rotate further, the cam follower 23a is forced by the protrusion 17a, and the resulting reaction force causes the cam follower carrier 27 to undergo cycloidal deceleration. At this stage, the eccentric shaft 16
moves toward the position closest to the cam follower 23a. When the cam 15 moves to a position where the eccentric shaft 16 is closest to the cam follower 23a, no driving force acts on the cam follower, and the cam follower carrier 27 has substantially zero speed. become a state.

As the crankshaft 11 continues to rotate further, a gradually increasing drive moment acts on the cam follower 23a, and the cycloidal acceleration and deceleration cycle of the cam follower carrier 27 is repeated.

In the case of the illustrated embodiment, the cam has three protrusions, so that during one rotation of the cam follower carrier 27, the cam follower 27 substantially accelerates from an apparent zero velocity state and substantially In other words, the vehicle undergoes six cycles consisting of deceleration to an apparent zero speed state. During this time, the cam 15 will rotate twice and the crankshaft 11 will rotate four times.

It will be appreciated that due to the forces within the motion conversion device, the cam follower passes through a so-called rest state with a limited speed.

As described above, the motion converting device according to the present invention uses two mechanisms consisting of the above-mentioned cam and cam follower, etc., in a "cat-mouse type", that is, members that rotate in a pair in the same rotational direction, that is, each member rotates in the same rotational direction. One member of the pair has a member that follows the other member, and these members rotate at an angular velocity that changes periodically, and the space between the two members undergoes rotational movement and the volume increases and decreases periodically. It is effective if applied to compress and expand the working chamber of a rotating mechanism of this type.

5 and 6 show an embodiment in which the motion conversion device according to the invention is implemented in a rotating mechanism of the type described above.

This rotation mechanism includes a crankshaft 31 on which a first cam 33 and a second cam 35 each having a plurality of protrusions are eccentrically mounted. The cams 33 and 35 are mounted on both sides of the rotating shaft of the crankshaft 31 at equal intervals (see FIG. 12, which will be described later).

Each cam has N protrusions, located equidistant from each eccentric axis, and
They are each arranged at equal intervals around an eccentric axis and rotate around this eccentric axis. Note that N here is an odd integer. In the illustrated embodiment, the cams each have three projections. The cam is configured to rotate in the same direction as the crankshaft, and the angular velocity of the crankshaft is 2/(N+
1) The structure is configured to rotate at twice the angular velocity as in the above embodiment. That is, although not shown in this embodiment, the two cams 33 and 35 are gear mechanisms similar to those in the first embodiment, and are configured to rotate as the crankshaft 31 rotates. There is.

A cam follower carrier comprising cam followers 37 arranged in a first pair cooperates with the first cam 33 and cam followers 38 arranged in a second pair.
A cam follower carrier comprising a cam follower is adapted to cooperate with the second cam 35. The cam and the paired cam follower carriers are each constructed in accordance with the present invention, so that by imparting a rotational movement with a constant angular velocity to the crankshaft, the cam follower carriers each have a rotational motion with a periodic angular velocity. You will receive exercise. The first cam and the second cam are configured to create a phase difference in the movement of their cam follower carriers.

In the illustrated embodiment, the arrangement is such that when one cam follower carrier undergoes a cycloidal acceleration, another cam follower carrier undergoes a cycloidal deceleration, or vice versa. In other words, the phase of the acceleration cycle of the cam follower is shifted by 180 degrees. This is achieved by arranging the first cam 33 and the second cam 35 so that they are 180 degrees out of phase with each other.

The rotation mechanism includes a casing 39 in which an annular working chamber 41 is formed. This annular working chamber 41 is formed from a pair of side walls (not shown), a cylindrical outer wall 42, and a cylindrical inner wall 46. These inner and outer walls are coaxial with the rotation axis of the crankshaft 31.

A first piston assembly 43 integrally formed with a cam follower carrier having a first cam follower 37 rigidly carries a plurality of pistons 47 disposed for operation within the working chamber 41. It has a base 45. This base 45 also has
It also serves as the carrier of the first cam follower.

A second piston assembly 49, integrally formed with a cam follower carrier comprising second cam follower 38, has a base 51 rigidly carrying a plurality of pistons 53. This base 51 also serves as a carrier for the second cam follower. The number of pistons 53 is the same as the number of pistons 47, and the pistons 53 and the pistons 47 are arranged alternately. In this way, each piston of one piston assembly is positioned between two pistons of the other piston assembly.

The first piston assembly and the second piston assembly are juxtaposed and have a base 45 thereof.
forms an inner wall 46 of the working chamber 41. As shown in FIG. 6, both pistons 47 and 53 are
It is mounted so that it extends in its longitudinal direction to the base portion of its counterpart, so that these piston portions are cantilevered.

The pistons 47 and 53 divide the working chamber 41 into a plurality of working spaces 55, and the angular length (length in the circumferential direction) of each is determined relative to the position of the adjacent piston. is variable. A sealing member (not shown) is arranged to maintain airtightness between the working chambers 55.

When the cam follower carriers are subjected to differential rotational motion (rotary motion with different periodic angular velocities) as described above, the piston assembly integral with each cam follower carrier is alternately accelerated and decelerated ( That is, when one piston is being accelerated, the other is being decelerated, or vice versa, so that adjacent pistons rotate toward or away from each other. In this way, the volume of the working space increases and decreases continuously.

FIG. 7 shows yet another embodiment, in which two pairs of cam followers 37 and 38 cooperate with a common cam 34. The cam 34 is such that the cam follower carrier receives differential rotational movement when the crankshaft 11 rotates at a constant angular velocity.

The rotation axis of the crankshaft 31 and the rotation axis of each cam follower carrier are centered. Therefore, by selectively applying pressure (squeezing force) between the crankshaft and the respective cam follower carrier, i.e. between the crankshaft and the piston assembly, it is possible to , it is possible to provide additional torque to the crankshaft or piston assembly.

Note that this pressure can be applied by mechanical means, hydraulic means, or electromagnetic means. In this case, pressure is also applied diametrically opposite to the axis of rotation of the crankshaft to create an unbalanced pressure on the bearings supporting the crankshaft and on the respective cam follower carriers and integral piston assemblies. It is preferable to minimize force.

In the case of a rotating mechanism used as a fluid pump, the crankshaft is driven at a constant angular velocity, fluid is taken into the working space when each working space approaches its maximum volume, and fluid is drawn into the working space when each working space approaches its minimum volume. It is sufficient to provide suitable intake and discharge means for the fluid to be discharged.

When a rotation mechanism is used as a compression ignition or spark ignition type internal combustion engine, air or an air-fuel mixture is sucked into the working space during the process of increasing the volume of the working space, which constitutes an intake stroke. Subsequently, as the volume of the working space decreases, the air or mixture is compressed, and when the volume reaches its minimum (or just before reaching the minimum volume stage), fuel is injected into the working space or ignited. Light the plug.

When used as a power plant, the expansion of the gas creates a "cat-and-mouse" action between the respective pistons, transmitting rotational torque to the crankshaft. To draw fluid (i.e., air or mixture) into the expanding working space during the intake stroke, and to expel fluid (i.e., spent combustion gases) from the working space during the exhaust stroke. is equipped with suction and evacuation mechanisms.

Note that the rotating mechanism can be configured to function as a two-stroke internal combustion engine or a four-stroke internal combustion engine.

Next, in order for the rotating mechanism to function as a motor-driven integrated fluid pump, one set of working spaces is configured to receive working fluid and perform the function of the mechanism's motor, and the remaining working spaces are configured to pump Configure it to function as a room. In this case, the piston and the sealing member interlocking with the piston prevent fluid from flowing between the motor or drive chamber and the pump chamber to prevent the pumped fluid from being contaminated by the working fluid. It's summery.

8-11 illustrate a rotating mechanism configured to operate as a four-stroke internal combustion engine. Basically, the structure is similar to the rotation mechanism shown in FIGS. 5 and 6. That is, this is a "cat-and-mouse" rotation mechanism, and the cams each rotate in the same direction as the crankshaft at an angular velocity of 2/(N+1) times the angular velocity of the crankshaft; the mechanism for this is not shown. Although the gear mechanism shown in Figures 1 and 7 is sufficient, the cam follower carrier rotates in the same direction as the cam, and since both cams are connected to the same crankshaft, both The cam follower also rotates in the same direction.

The first piston assembly 43 and the second piston assembly 49 each have an annular working chamber 4 .
It has six radial pistons 47 and 53 operating within one. This rotation mechanism includes a suction hole 61 and a discharge hole 63 opened in the side wall of the casing 39.
are provided. This suction hole 61 and discharge hole 6
3 means an angular width (width in the circumferential direction) that is substantially the same as the angular width (width in the circumferential direction) of the piston, and which is the width of the piston when the working space 55 is at its maximum volume and minimum volume. It is configured to be closed when the opening is closed.

Since each piston assembly has six radial pistons, the working chamber 41 has twelve working spaces. Additionally, three intake holes and three exhaust holes are required for the rotating mechanism to function as a four-stroke internal combustion engine.

In the state shown in FIG. 8, the first piston assembly 43 is in the leading position, and the first piston assembly 43 has been rotated 30 degrees (counterclockwise in the figure) from the rest position of the first piston assembly 43. position (that is, the peak position of cycloidal acceleration), and the second piston assembly 49 in the following position is located at the peak position of cycloidal deceleration.

Internal combustion engines typically require a starting motor to initiate the compression cycle. Ignition is performed in the above state, and the expansion of the ignited gas in the working chamber 55c causes the piston to rotate in the direction given by the starter motor (counterclockwise in the figure). Therefore, in this state,
Both piston assemblies continue to rotate at substantially the same angular velocity, and the working spaces are at their maximum and minimum volumes, respectively.

The working space 55a is completely evacuated after the completion of the exhaust stroke, the working space 55b is filled with the combustible mixture after the completion of the intake stroke, and the working space 55c is filled with the compressed combustible mixture after the completion of the compression stroke. The air-fuel mixture is filled and the working space 55d is fully expanded upon completion of the power stroke.

When the combustible air-fuel mixture compressed in the working space 55c is ignited, the first piston assembly 43 undergoes cycloidal acceleration due to the expansion of the generated combustion gas, and as a result, rotational torque is applied to the crankshaft 31. will be given.

When the first piston assembly 43 continues to be accelerated (FIG. 9), the suction hole 61 is inserted into the working space 5.
5a, the working space becomes the suction stroke. As the second piston assembly 49 continues to rotate, the discharge hole 63 comes into communication with the working space 55d. It should be noted that at this stage, the second piston assembly 49 is undergoing cycloidal deceleration.

Next, FIG. 10 shows a stage in which the second piston assembly 49 is at rest and the first piston assembly 43 continues to rotate.

At the end of the output stroke of the working space 55c, both piston assemblies are in the position shown in FIG. That is, the first piston assembly 43
is in a position following the second piston assembly 49 (as a result of a "cat-and-mouse" action), the suction hole 61 is closed by the piston of the second piston assembly 49, and the discharge hole 63 is closed by the piston of the second piston assembly 49. The position is closed by the piston of the first piston assembly 43. After this, the cycle described above is repeated. On each power stroke, the particular piston assembly undergoing acceleration first transmits rotational torque to the crankshaft via its cam, while the crankshaft imparts rotational energy to the other piston assemblies.

When configured as shown in FIGS. 8-11, 4
The stroke internal combustion cycle will be performed three times.

FIG. 12 is a sectional view showing an embodiment of a "cat-mouse type" rotation mechanism using the rotation mechanisms shown in FIGS. 8 to 11. FIG.

This rotation mechanism has a fixed housing 131 in which a crankshaft 133 is rotatably supported. The first cam 135 and the second cam 137 each having a plurality of protrusions have the shapes described above, and are rotatably mounted on the crankshaft 133 eccentrically with respect to the rotation axis of the crankshaft 133. has been done. Both cams 135 and 137
are arranged equidistantly on both sides of the rotation axis of the crankshaft 133. Both cams 135 and 137
is 2/(N) of the angular velocity of the crankshaft 133
+1) times the angular velocity in the same direction as the crankshaft 133.

The first pair of cam followers 139 and the pair of second cam followers 141 each correspond to the first cam 135
and the second cam 137. The cam and each cooperating cam follower pair are constructed in accordance with the present invention, so that when the crankshaft 133 is subjected to rotational movement of a constant angular velocity, the cam follower (and thus the cam follower carrier) It is designed to experience periodic angular velocity. The first cam 135 and the second cam 137 are configured such that the first cam follower pair 139 and the second cam follower pair 141 undergo differential rotational motion. This differential rotational motion involves an acceleration cycle of the cam follower pair such that when one cam follower pair is experiencing acceleration, the other cam follower pair is experiencing deceleration, and vice versa. Preferably, the phases are shifted by 180°.

A first piston assembly 143 is adapted to cooperate with a first pair of cam followers 139 and a second piston assembly 145 is adapted to cooperate with a second pair of cam followers 141, thereby similar to the previously described embodiments. The piston assemblies operate in conjunction with respective cam followers. The first piston assembly 143 includes a plurality of pistons 147
The second piston assembly 145 includes a plurality of pistons 149, and the number of these pistons is the same. These pistons 1
47 and 149 are the working chamber 1 (as shown in Fig. 6).
51 and are configured to operate in a state where they are inserted into each other.

As described above, the motion converting device of the present invention is applicable to a "cat-mouse" type rotation mechanism having a plurality of actuation mechanisms. For example, those skilled in the art will easily understand that it is possible to integrally configure the engine and the pump driven by the engine.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of the motion conversion device, FIG. 2 is a schematic front view of the motion conversion device with the cam follower in the rest state, FIG. 3 is a schematic front view of the motion conversion device with the cam follower in the maximum acceleration state, and FIG. Fig. 4 is a schematic front view of the motion converting device with the cam follower in its maximum speed state, Fig. 5 is a schematic front view showing an embodiment of a rotating mechanism incorporating the motion converting device of the present invention, and Fig. 6 is a schematic front view of the rotating mechanism. a first piston assembly and a second piston assembly;
FIG. 7 is a schematic front view showing another embodiment of a rotating mechanism incorporating the motion conversion device of the present invention; FIG. 8 is a schematic front view of a rotating mechanism operating as an internal combustion engine; 9 is a schematic front view of the rotation mechanism of FIG. 8, with the first (front) cam shown rotated 30° from the rest position of each pair of cam followers; 10 is a schematic front view of the rotation mechanism of FIG. 8, with the first cam shown rotated 35° from the rest position of each pair of cam followers; FIG. 11 is a schematic front view of the rotation mechanism of FIG. 8, with the first cam and each pair of cam followers shown in the rest position, rotated 60° from the rest position; FIG. Figure 12 shows the position rotated 90 degrees from the position in Figure 8 to Figure 1.
FIG. 2 is a cross-sectional view showing an embodiment of a "cat-mouse type" rotation mechanism using the rotation mechanism shown in FIG. 11... Crankshaft, 12... Center shaft,
15...Cam, 16...Eccentric shaft, 17...Protrusion, 23...Cam follower, 27...Cam follower carrier, 31...Crankshaft, 33...
...First cam, 34...Common cam, 35...Second cam
cam, 37...first cam follower, 38...
Second cam follower, 39...Casing, 41
... annular working chamber, 42 ... outer wall, 43 ... first piston assembly, 45 ... base, 46 ... inner wall, 47 ... piston, 49 ... second piston assembly, 51 ... base, 53 ……piston,
55... working space, 61... suction hole, 63... discharge hole.

Claims (1)

[Scope of Claims] 1. A cam that is mounted to rotate around an eccentric shaft that is eccentric with respect to the central axis, the eccentric shaft is rotatable around the central axis, and the cam has N protrusions. a central axis; A drive mechanism that provides relative rotation between the central shaft and the cam when the eccentric shaft rotates around the eccentric shaft, that is, when the cam rotates around the eccentric shaft.
2/ of the angular velocity of the eccentric shaft rotating around the central axis
It is composed of a drive mechanism that regulates the relative rotation between the central axis and the cam so that the cam rotates around the eccentric axis at an angular velocity of (N+1) times, and around an axis that substantially coincides with the central axis. a pair of rotatable cam followers, wherein the cam and the cam follower are arranged such that the cam follower is in contact with the cam on both sides of the central axis and is equidistant from the central axis, and the eccentric shaft moves around the central axis at a substantially constant speed. When rotated,
It consists of a cam curve that is formed so that the cam follower carrier that supports the cam follower undergoes one cycle of acceleration from a resting state and deceleration to a resting state 2N times each time it rotates. A motion conversion device comprising a cam and a cam follower. 2. The motion conversion device according to claim 1, wherein the cam follower is mounted on a cam follower carrier that is rotatable around a central axis. 3. The motion converting device according to claim 2, wherein each of the cam followers comprises a roller whose rotational axis is substantially parallel to the central axis. 4. The outermost position of each protruding part of the cam,
2. The motion conversion device according to claim 1, wherein the cam is formed such that the distance between the cam contact surface and the radially outer position is equal to the distance between the cam contact surfaces of the cam follower. 5. The cam is rotatably mounted on an eccentric portion of a crankshaft, the rotating shaft of the crankshaft forms the central axis, and the central axis in the longitudinal direction of the eccentric portion forms the eccentric axis. The motion conversion device according to item 4. 6. The drive mechanism that provides relative rotation between the central shaft and the cam includes an internal gear coaxial with the cam and fixed to the cam, and an external gear whose central axis is coaxial with the internal gear and meshes with the internal gear. , and an external gear fixed against rotation with respect to a fixed reference frame. 7 A cam that is mounted to rotate around an eccentric shaft that is eccentric to the central axis, the eccentric shaft is rotatable around the central axis, the cam has N protrusions, and the cam has N protrusions. A cam whose outermost position is located at an equal distance from the eccentric axis, and which is arranged at equal intervals around the eccentric axis, where N is an odd integer other than 1, and an eccentric axis around the central axis. A drive mechanism that provides relative rotation between the central shaft and the cam when the cam rotates, that is, when the cam rotates around the eccentric shaft.
2/ of the angular velocity of the eccentric shaft rotating around the central axis
It is composed of a drive mechanism that regulates the relative rotation between the central axis and the cam so that the cam rotates around the eccentric axis at an angular velocity of (N+1) times, and around an axis that substantially coincides with the central axis. a pair of rotatable cam followers, wherein the cam and the cam follower are arranged such that the cam follower is in contact with the cam on opposite sides of the central axis and is equidistant from the central axis, and the eccentric shaft moves at a substantially constant speed about the central axis. When rotated,
Composed of a cam and cam follower with a cam curve formed so that the cam follower undergoes one cycle of acceleration from a resting state and deceleration to a resting state 2N times each time the cam follower carrier that supports the cam follower rotates once. A rotating mechanism equipped with a motion conversion device, which has two sets of at least one cam and at least one pair of cam followers, and the at least one cam is mounted on a crankshaft whose axis is coaxial with the central axis. and the two sets of at least one pair of cam followers are adapted to receive differential motion, and the piston assembly cooperates with each of the pair of cam followers such that the piston assembly receives the same motion as each of the pair of cam followers. Each piston assembly consists of the same number of pistons, an annular working chamber whose center axis is coaxial with the axis of rotation of the crankshaft, and fluid suction and fluid ejection means cooperating with the annular working chamber, The pistons of the piston assembly are arranged in an alternating relationship, and the annular working chamber is divided into a plurality of working spaces, in which a pair of cam followers are operated. A rotation mechanism characterized in that a working space is expanded and contracted alternately by differential rotation motion between two sets. 8. The rotation mechanism according to claim 7, which has two cams, and each pair of cam followers cooperates with one cam. 9. A rotation mechanism according to claims 7-8, wherein the differential movement is in the form of a 180° out-of-phase phase shift in the acceleration cycle of the piston assembly. 10 The fluid suction means and the fluid discharge means are comprised of a plurality of pairs of holes provided at intervals around an annular working chamber, one of the pair of holes being a suction hole and the other hole being a discharge hole. a hole through which the piston passes continuously during differential movement of the piston, and wherein the suction hole and the discharge hole are at most substantially the same as the angular width of the piston. , wherein the pistons are arranged to be located at respective hole positions so as to close the holes with some of the working spaces at a minimum volume and the remaining working spaces at a maximum volume. Items 7 to 9
The rotation mechanism described in section. 11. Claims 7 to 1, each piston assembly comprising 2N pistons.
The rotation mechanism according to item 0. 12. The rotation mechanism according to claim 7, wherein the cam has five protrusions. 13. The rotation mechanism according to claim 8, wherein each cam has three protrusions.